#pragma once
#include<stdio.h>
#include <stdlib.h>
#include <assert.h>

typedef struct BTTree {
	int val;
	struct BTTree* right;
	struct BTTree* left;
}BT;

BT* BuyNode(int x);
void PreOrder(BT* root);
void InOrder(BT* root);
void BackOrder(BT* root);